The present invention relates to apparatus for controlling the position and location of a stationary device constituting a component of a paper machine and which acts on the web being manufactured or on a fabric carrying the web over a dimension thereof transverse to the direction of travel of the web.
More particularly, the present invention relates to position and location controlling apparatus by which the distance of a stationary device from the web or fabric and/or the angular orientation of the stationary device is controlled and wherein a frame portion of the stationary device is carried on both ends of the frame structure of the paper machine through the mediation of the control apparatus.
As used herein, a stationary device acting on a web will be understood as including a device which will influence the web, e.g., the dewatering of the web or the running of the web, without substantially directly contacting the same.
In the illustrated embodiment of the apparatus of the present invention, the stationary device constitutes a dewatering element employed on the wire section of the paper machine. However, it is understood that the present invention is also applicable to controlling the position and location of other devices which affect the web and its running, e.g., in connection with the drying of the web.
Regarding the state of the art with which the present invention is concerned, reference is made by way of example to U.S. Pat. Nos. 3,323,982 and 3,535,201, both of which concern dewatering elements situated in the wire section of the paper machine. More particularly, U.S. Pat. No. 3,323,982 discloses apparatus for adjusting the height of a foil strip relative to a web including control screws and wherein a beam carrying the foil strip is connected to the paper machine frame by swivel bearings so that the foil beam as a whole can be tilted around the bearing. However, since an adjustment in the angular orientation of the foil will also unavoidably result in an adjustment in the height of the foil, the precise control of the position and location of the foil strip is complicated and time-consuming.
U.S. Pat. No. 3,535,201 discloses an arrangement wherein the ends of the beam which carry the foil strip are each affixed tothe frame structure by two screws which pass through elongated holes. In order to adjust the angular orientation of the foil strip, the latter can be turned in curved guides which are arranged such that adjustment of the foil angle will not affect the height position, i.e., the distance of the foil strip from the web. Rather, in this arrangement, the height of the foil strip is adjusted by means of separate control screws.
Both of the arrangements described above have the drawback that the control screws employed to control the position and location of the foil strip fail to provide a surficiently rigid and sturdy support of the foil beam on respective substructures. Moreover, the accuracy of the adjustment of the position of the foil strip as well as the ease with which such adjustments are made in the prior art arrangements discussed above also leave room for improvement.